Aquarium



FIG. 1 is a perspective view of an aquarium showing my new design;

FIG. 2 is a front view of the aquarium, the rear view being identical thereto;

FIG. 3 is a top view of the aquarium;

FIG. 4 is a side view of the aquarium from the left side, the right side view being identical thereto; and,

FIG. 5 is a bottom view of the aquarium. 

The ornamental design for an aquarium, as shown and described. 